Friedreich's ataxia

Definition

Friedreich's ataxia is a rare disease passed down through families (inherited) that affects the muscles and heart.

Alternative Names

Spinocerebellar degeneration

Causes, incidence, and risk factors

Friedreich's ataxia is caused by a defect in a gene called Frataxin (FXN). This gene is located on chromosome 9. Changes in this gene cause the body to make too much of a part of DNA called trinucleotide repeat (GAA). Normally, the body contains about 8 to 30 copies of GAA. Those with Friedreich's ataxia have as many as 1,000 copies. The more copies of GAA a patient has, the earlier in life the disease starts and the faster it gets worse.

Friedreich's ataxia is an autosomal recessive genetic disorder. This means you must get a copy of the defective gene from both your mother and father.

Symptoms

Symptoms are caused by the wearing away of structures in areas of the brain and spinal cord that control coordination, muscle movement, and other functions. Symptoms generally begin in childhood before puberty, and may include:

Blood sugar (glucose) tests may reveal diabetes or glucose intolerance. An eye exam may show damage to the optic nerve, which usually occurs without symptoms.

Treatment

Treatment for Friedreich's ataxia includes:

Counseling

Speech therapy

Physical therapy

Walking aids or wheelchairs

Orthopedic interventions (such as braces) may be needed for scoliosis and foot problems. Treatment of heart disease and diabetes may help improve the quality and duration of life.

Expectations (prognosis)

Friedreich's ataxia slowly gets worse and causes problems performing everyday activities. Most patients need to use a wheelchair within 15 years of the disease's start. The disease may lead to early death.